The circumference of a circle = \(\pi d\) or \(2\pi r\). Look at the sector of the circle shown below. To calculate the length of the arc, we need to know what fraction of the circle is shown.

Calculate the arc length to 2 decimal places. First calculate what fraction of a full turn the angle is. 90° is one quarter of the whole circle (360°). The arc length is \(\frac{1}{4}\) ...